There are tunnels under all that area, there are tunnels and subfloors to the AT&T/NSA building and back to the AT&T skyscraper. That building has multiple subfloors. It also had a diamond hazard sign of 3-4-1-W which means inside that place was restricted for firefighters, NO WATER, Explosive Gases, fuels, coolants and toxic, MAX DANGER level 4
There are tunnels under all that area, there are tunnels and subfloors to the AT&T/NSA building and back to the AT&T skyscraper. That building has multiple subfloors. It also had a diamond hazard sign of 3-4-1-W which means inside that place was restricted for firefighters, NO WATER, Explosive Gases, fuels, coolants and toxic, MAX DANGER level 4